I won't disagree with your point of view. But I believe that a strong primal instinct still very much alive in all humans. Primal instinct would NOT really be applicable to the situations you described such as abolishing slavery, those are collaborative efforts made with some sort of group consensus, those objectives were achieved over periods of time...most of them hundreds of years.
A primal instinct, as I was talking about, is momentary...like fight or flight. He saw a women get hit, felt the rush and allowed it to take over instead of quelling it. Simple.
Primal instincts/reactions do not require legislation.